A. It is Basic
for example,
NaOH → Na⁺(aq) + OH⁻(aq)
Ba(OH)₂ → Ba²⁺(aq) + 2OH⁻(aq)
Ca(OH)₂ → Ca²⁺(aq) + 2OH⁻(aq)
pH>7
The only explanation, Rutherford suggested in 1911, was that the alpha particles were being scattered by a large amount of positive charge concentrated in a very small space at the center of the gold atom.
The untrue statement is that they high melting points.
The covalent compounds are the compounds exhibiting strong intra-molecular bonds. This is due to the tightness of the atoms within the covalent molecules. The force of attraction between the individual molecules in a covalent compound seems to be weak. The covalent compounds exhibit weak intermolecular forces that hold the atoms together due to this they have a low melting point.
To get the molarity you need to follow this equation
moles of solute
Molarity (M = -----------------------
Liters of solution
But before you apply that equation you need to find the moles of solute and the liters of solution. Follow this equation
Na2SO4 + BaCl2 = BaSO4 + 2 NaCl
Solution
Moles of BaSO4 = 5.28 g
---------------
233.43 g / mol
= 0.0226 moles
Moles of NaSO4 = 0.0226
0.0226 mole
Molarity = -----------------
0.250 L
= 0.0905 mol / L
So the answer is 0.0905 mol / L